This invention relates generally to tower guys and more particularly to a unique assembly of strands to form a tower guy.
The increased use of EHV (extra heavy voltage), e.g. 500 KV and 750 KV, power transmission lines has resulted in the design of a variety of towers. Many of these towers are as much as 100 feet high and are guyed. Installation of some of these towers has been by use of helicopter lifts from the assembly point to the erection site. Tower foundations are set beforehand and the assembled tower is carried to the site by helicopter. During tower erection the guys attached to the tower are initially tensioned as the tower is set on its foundation which permits the release of the helicopter. Crews then return to complete the tower plumbing by adjusting the guy tension to the proper value.
Guy strands used on utility towers are often single lengths of 3/4" or 7/8" diameter 1.times.19 construction. Such strands are more expensive than multiple parallel 1.times.7 strands of smaller diameter having a composite breaking strength equal to or exceeding that of the 1.times.19 strand.
A 1.times.7 strand is defined as having a center wire around which six wires are twisted in a helical fashion. All seven wires are of the same nominal diameter.
A 1.times.19 strand is defined as having a center wire around which a first layer of six wires are twisted in a helical fashion. A second layer of twelve wires is twisted in helical fashion over the first layer of six wires. All nineteen wires are of the same nominal diameter.
Prior to this invention multiple strands used for guying involved individual fastening of each of the strands at the tower and to a tension equalizing device at the ground anchor in a costly and complex procedure.